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Nrren STATES PATENT FFICE.

OTTO P. AMEND, OF YORK, N. Y.

success or TAWING.

SPECIFICATION forming part of Letters Patent N0. 542,971, dated July 16,1895.

Application filed April 5, 1894:- Serial No. 506i (N0 p n I To all whom it may concern.-

Be it known that 'I, OTTO P. AMEND, a citizen of the United States, residing in the city, county, and State of New'York, have invented a new and useful Process of Tanning and Dyeing, of which the following is a specification My invention relates specially to the tanning and dyeing of hides, skins, pelts, and

leather, and to the dyeing of hair and for of" fur-bearing and other animals, and feathers; yet it is useful for dyeing other material.

Hitherto it has been the custom to tanand dye hides, skins, or pelts at difierent times, for the reason that one process frequently seriously interfereswith the other, and this'is. "especially true of tanning'the skin and dyeing the hair or for of fur-bearing and other animals. What has been efiective for the hide or skin has been destructive or detrimental to the hair or fur, and vice versa.

By the process described herein the tanningand dyeing are conducted simultaneously and with great advantage one to the other. In fact, the means employed to effect one is in part the means enfployed to attain the other. They are cooperative and co-ordinate parts of one and the same process.

In carryingout myinventiomI first remove all fat and fatty matter from the article to be treated, by any well-known means, and then immerse the hides, skins, pelts, leather or feathers, as the case may be, in a cold aqueous solution of free chromic acid,by means of which a chemical change is efiectedin' the constituents of the article treated or in some of them, the free chromic acid combining .chromateinthe material.

organic chromate, formed in thematerial by the combination of some of its parts with chromic acid, by the employment of an arcmatic amine or a compound thereof. I'have found that by this organic reduction of the organic chroniate a most thorough and complete tanning as well asdyeing process is effected simultaneously, and that by changing the amine used difierent colors may be obtained which are fixed and fast. I have also found thathair or fur attached to a hide or skin is very satisfactorily preserved and uniformily dyed by this process. It will also preserve and dye the hair or fur when sep-,

I reducethe organic chromate (formed in the articles by their exposure to the action of the chromic-acid solution) by immersing the material containing the organic chromate in an aromatic amine solution of about five per cent. strength, thus exposing the organic chromate to the action of the aromatic amine solution. The latter solution may bemade but I prefer to use the ordinary chloride of aniline or the so called aniline salt of commerce for the purpose.

Having described my invention, what I claim, and desire to secure by Letters Patent,

The process of tanning and dyeing which consists in subjecting the material to be treated to the action of a chromic acid solution, and then to the reducing action of an aromatic amineor a compound thereof, substantially as set forth.

OTTO P. AMEND. Witnesses:

ANDREW SCHENCK, EDWARD B. AMEND. 

